Theoretical investigation of the electron velocity in quantum Hall bars, in the out of linear response regime

TL;DR

This paper provides a theoretical analysis of electron velocity in quantum Hall systems under out-of-linear-response conditions, revealing how current and impurities influence incompressible strip widths.

Contribution

It introduces a nonlinear screening theory approach to study electron velocity distribution and asymmetry in quantum Hall bars beyond linear response.

Findings

Incompressible strip width increases linearly with current intensity.

Strip width decreases with impurity concentration.

Asymmetry in strips depends on current and impurities.

Abstract

We report on our theoretical investigation of the electron velocity in (narrow) quantum-Hall systems, considering the out-of-linear-response regime. The electrostatic properties of the electron system are obtained by the Thomas-Fermi-Poisson nonlinear screening theory. The electron velocity distribution as a function of the lateral coordinate is obtained from the slope of the screened potential within the incompressible strips (ISs). The asymmetry induced by the imposed current on the ISs is investigated, as a function of the current intensity and impurity concentration. We find that the width of the IS on one side of the sample increases linearly with the intensity of the applied current and decreases with the impurity concentration.